Installation of a MIDEA EVOX G3 central heat pump in Le Plateau-Mont-Royal, Montreal

A central installation discreetly integrated into a Plateau-Mont-Royal brick facade

In Le Plateau-Mont-Royal, installing a central heat pump often raises a very different question from the one encountered in a suburban home with a large lot: how can you integrate a complete HVAC system into an existing building without sacrificing access, basement windows, the appearance of the secondary facade, or the available outdoor space?

This MIDEA EVOX G3 installation completed by our AirGreen team offers an excellent example.

The project photograph shows a long red-brick facade, a concrete foundation, a basement window, and already well-established landscaping. The Midea condenser is installed at the end of the wall on a raised metal support, while a long run of lines has been grouped inside a reddish-brown line-hide that runs horizontally along the transition between the brick and the foundation.

It is precisely this finish that makes the project interesting.

Rather than leaving several lines, cables, and insulation exposed along a large portion of the wall, we concentrated the run inside a clean, continuous exterior enclosure. The line follows the architecture of the house, passes above the basement window rather than visually cutting across it, and heads toward the heat pump installed at the end of the building.

Midea’s documentation presents the EVOX G3 as a line of ducted central systems with inverter technology, designed in particular to facilitate the modernization of existing residential heating systems.

The real challenge of the project: crossing a long facade without making it look as though a mechanical system had been added

In some central installations, the distance between the outdoor unit and the mechanical room is very short. The refrigerant lines enter the building almost directly behind the condenser.

Here, the situation was different.

The photo clearly shows a significant horizontal run along the brick wall. In a dense architectural area like Le Plateau-Mont-Royal, leaving a long refrigerant line simply covered with black insulation would have produced a much less polished visual result.

We therefore treated the outdoor routing as an integral part of the project.

The pipe cover follows a regular horizontal line along the foundation and then includes a vertical drop near the starting point. Its reddish-brown color remains consistent with the existing masonry, making the technical route much less prominent on the facade.

Why the line runs above the basement window

A basement window is located directly below part of the route.

Poor planning could have created several problems:

• running in front of the window;
• reduced access for maintenance;
• visual clutter;
• the risk of complicating a future window replacement;
• an unnecessarily irregular refrigerant line path.

Instead, we routed the line above the opening, in an area already marked by the transition between the foundation and the brick.

This type of detail is particularly important for an HVAC installation in Montreal, where each facade may have several obstacles: basement windows, meters, downspouts, windows, balconies, fences, stairs, or shared passageways.

An outdoor installation at the end of the facade rather than in the middle of the wall

The heat pump itself is positioned at the far right of the photograph, near a landscaped retaining wall.

This choice keeps the central part of the wall relatively clear. It also avoids placing most of the equipment directly in front of the basement window.

The unit rests on a metal wall mount, keeping it above the ground.

In Le Plateau-Mont-Royal, where side and rear spaces can be narrow, a well-chosen wall mount can be particularly useful. It reduces the footprint occupied on the ground and helps preserve circulation space around the building.

Why raising a heat pump in Montreal remains essential

An outdoor installation that looks perfect in July must also function properly in January.

In heating mode, a heat pump must periodically perform a defrost cycle. Water is then produced beneath the unit before potentially freezing on the ground.

A unit installed too low may gradually end up surrounded by:

snow, ice, frozen water, leaves, and accumulated debris.

The heat pump visible at our worksite is installed high enough to preserve significant space beneath the unit.

This height also makes maintenance easier and limits the risk of the ground level or future landscaping gradually approaching the bottom of the condenser.

The neighboring retaining wall also had to be taken into account

Beside the heat pump, a small retaining wall made of landscaping blocks can be seen.

This is exactly the kind of constraint we examine before determining the unit's final position.

A heat pump must maintain the necessary clearances around its heat exchanger and air-discharge area. It is therefore not enough to find a surface large enough to place the unit.

We must ensure that:

• air can circulate;
• the panels can be removed;
• the connections remain accessible;
• nearby obstacles do not create significant recirculation;
• the homeowner can still maintain the property.

An outdoor architecture with horizontal discharge suited to compact installations

For the EVOX G3 range, Midea uses an outdoor architecture with horizontal discharge, combined with a vertical heat exchanger.

In its documentation, the manufacturer explains that this arrangement is intended to provide more uniform airflow through the heat exchanger and better heat-transfer efficiency when conditions become colder.

This format is particularly interesting for certain urban applications in Montreal.

Unlike a large cube-shaped heat pump with vertical discharge, a horizontal-discharge unit can often be installed closer to a facade, provided the required clearances in front of and around the unit are respected.

However, choosing the orientation remains essential: avoid discharging air directly against a fence, wall, or obstacle located too close.

The MIDEA EVOX G3 and heating in extreme cold

For a residence in Plateau-Mont-Royal, a central heat pump is not merely an air-conditioning appliance.

Its main advantage also lies in its ability to provide heating during much of the Quebec winter.

Midea states that the EVOX G3 Extreme Heat platform can operate continuously down to -30 °C. The brochure also indicates, under certain test conditions, up to 100% heating capacity at approximately -25 °C. However, the manufacturer specifies that some of these results come from tests conducted on a three-ton Midea system.

This is an important nuance.

We never consider the statement "down to -30 °C" proof that every home can be heated fully to that temperature with any EVOX G3 capacity.

The real question is always:

How many BTUs does the building lose when the outdoor temperature drops?

The role of the M-Powevi compressor

Midea also uses its M-Powevi technology to support heating performance at low temperatures.

According to the technical documentation, the system can inject intermediate-temperature vapor into the compressor when conditions become extremely cold, increasing the total amount of compressed refrigerant and helping preserve heating capacity.

For the homeowner, this technology essentially means a heat pump designed to retain its capacity longer as the thermometer drops.

EVOX G3: several capacities, not a single heat pump

It is important not to consider “EVOX G3” as a specific capacity.

The range includes several configurations.

The Midea technical table includes, among other things:

These figures correspond to the various Extreme Heat configurations presented by Midea.

The range reaches up to 19 SEER2, 12.5 EER2, and 10.8 HSPF2, depending on the selected combination.

The photo of our project does not allow the complete model number to be read with sufficient precision. We therefore do not artificially assign it an exact capacity based solely on the outdoor dimensions.

To determine an installation's actual performance, you must always check the outdoor unit, the indoor unit, and their certified combination.

Behind the exterior finish of Plateau-Mont-Royal: all the work that makes a central heat pump operate properly

A long refrigerant line does not mean that the installation can be neglected

The outdoor routing is one of the most distinctive elements of this project.

When a refrigerant line must cover a greater distance, we pay particular attention to its routing, supports, insulation, and the limits prescribed by the manufacturer.

The goal is not merely to achieve an aesthetic result.

A good installation must also allow for:

• a properly executed refrigerant connection;
• continuous insulation of the appropriate pipe;
• mechanical protection;
• consistent water drainage when necessary;
• a route that remains inspectable.

The reddish-brown enclosure visible in the photo therefore serves both to protect the connections and improve the appearance of the facade.

The ductwork inside is just as important as the outdoor routing

A central heat pump does not directly heat the room where its indoor unit is located.

It must move air throughout the house.

That is why we must consider the existing ductwork:

• supply ducts;
• air returns;
• plenum dimensions;
• filter;
• static pressure;
• airflow to each floor;
• balancing the registers.

On the Plateau-Mont-Royal, several properties have undergone successive renovations. The duct system may sometimes have been modified several times before new equipment is installed.

Installing a high-performance heat pump without understanding this system can severely limit the result.

Computational Constant Airflow 2.0: a particularly useful feature for renovations

The EVOX G3 uses Computational Constant Airflow 2.0 technology.

Midea explains that the fan can adjust its operation to adapt to different duct and filtration conditions. In the example presented in the documentation, the system maintains 1,200 CFM up to 1.2 in. of water column static pressure.

The system also offers up to 60 airflow adjustment levels.

This flexibility is particularly useful when replacing an old furnace.

However, this does not mean that all duct problems disappear.

If the pressure is too high because of an undersized return air duct, a filter that is too small, or a poorly constructed transition, the right solution is always to identify the restriction.

From 618 to more than 1,800 CFM depending on the indoor units

The EVOX G3 documentation clearly shows how much airflow requirements can vary depending on capacity.

The air handlers listed have airflow rates ranging approximately from 618 CFM to more than 1,800 CFM, depending on the equipment size and selected speed.

That is why replacing a three-ton old system with a larger new heat pump simply “to be sure” is not a good approach.

The duct system must be able to distribute the additional air.

A modular indoor unit for hard-to-access basements

Montreal homes do not always have spacious mechanical rooms.

Midea therefore designed the EVOX G3 air handler for several configurations: upflow vertical, downflow, right horizontal, left horizontal, and certain low-boy installations when available height is limited.

The manufacturer also offers widths ranging approximately from 14.5 to 21.5 inches depending on capacity, as part of a replacement approach for certain existing furnaces.

In a home in the Plateau with a low basement ceiling, existing beams, and ducts already installed, this modularity can significantly reduce integration complexity.

Auxiliary heating must work with the heat pump, not against it

Midea offers auxiliary electric heating kits of up to 25 kW, depending on the application, with several operating stages.

Auxiliary heating remains important in Quebec.

However, an incorrect setting may allow it to run too often, reducing the energy advantage of an inverter heat pump.

During commissioning, we therefore want to coordinate:

the heat pump, thermostat, auxiliary heating, and the building's actual needs.

Communicating or 24 V thermostat: useful flexibility in existing buildings

Completely rewiring a thermostat in a finished building can be a significant undertaking.

The EVOX G3 is compatible with 485 communicating mode as well as 24 V controls for certain configurations, including third-party thermostats.

Midea also offers its communicating thermostat and SmartHome app, with scheduling, comfort adjustment, monitoring of certain consumption information, and diagnostic functions.

This flexibility is particularly useful in a Plateau renovation, where avoiding unnecessary opening of walls and ceilings is often a considerable advantage.

R-454B and the transition to A2L systems

The EVOX G3 uses R-454B refrigerant, classified as A2L.

Midea's documentation indicates a global warming potential of 466 and confirms the use of this refrigerant in its EVOX central systems lineup.

For the user, daily operation does not change: the temperature is still set at the thermostat.

For the contractor, however, A2L equipment requires adapted procedures, tools, and practices.

This is another reason why the installer's expertise remains just as important as the heat pump brand.

LogisVert: an attractive incentive, but only with the eligible combination

For Plateau-Mont-Royal homeowners, Hydro-Québec's LogisVert program may help cover the cost of an eligible heat pump.

When all requirements are met, Hydro-Québec currently provides $50 per 1,000 BTU/h at -8 °C for an eligible ENERGY STAR heat pump and $120 per 1,000 BTU/h at -8 °C when it is ENERGY STAR - Cold Climate certified.

For equipment installed since November 26, 2025, ENERGY STAR certification is part of the eligibility requirements.

The amount should therefore never be calculated simply from the nominal capacity figure shown on a quote.

Hydro-Québec allows users to search for the combination using the AHRI number or the unique ENERGY STAR identifier and specifies that its official list of eligible heat pumps prevails in the event of a discrepancy with the search tool.

At AirGreen, this is the exact reference we use to verify financial assistance before confirming an amount with the customer.

What this Plateau-Mont-Royal installation reminds us to check before any project

An installation like this one summarizes several best practices that become especially important in Montreal’s urban neighbourhoods:

1. Choose the outdoor location before deciding on the exact route of the lines.
2. Preserve basement windows and access to them.
3. Protect long refrigerant lines rather than leaving them exposed.
4. Integrate the line-hide finish into the façade when the route is highly visible.
5. Raise the heat pump high enough to account for snow and defrosting.
6. Keep the technical panels accessible.
7. Check the duct network before definitively choosing the capacity.
8. Confirm the AHRI combination before announcing a LogisVert rebate.

An exterior finish that reveals the quality of the planning

On this Plateau-Mont-Royal project, the most notable element is ultimately not just the heat pump.

This is the route leading to it.

A long mechanical connection had to cross a brick façade with a basement window and several architectural constraints. We chose to group it into a continuous, structured route rather than let the different elements appear separately.

At the far end of the façade, the MIDEA EVOX G3 is installed high on its support, in an area where it can operate without taking over the central part of the wall.

This project clearly illustrates our approach at AirGreen: the quality of a central heat pump installation is measured by more than the equipment’s SEER2 or HSPF2 performance. It is also evident in the routing of the lines, the location chosen, ease of maintenance, and how the new system integrates into a house that existed long before it.

Whether the project is located in Le Plateau-Mont-Royal, elsewhere in Montreal, Laval, Longueuil, on the North Shore, or on the South Shore, our objective remains the same: to design an HVAC installation that works properly, remains accessible, and integrates cleanly into the building.